Vacuum-pump.



C. N. SOWDEN.

VACUUM PUMP.

APPLICATION FILED A R.11.1914.

1,1 6,207. 1 Patented Nov. 16, 1915.

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W/T/VESSES C N. SOWDEN.

VACUUM PUMP.

APPLICATION FILED APR. 11. 1914.

INVENTOR Patented Nov. 16,

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WITNESSES d w O M 6 1 m a BY /KZY'7 V if ATTORNEYS C. N. SOWDEN.

VACUUM PUMP.

APPLICATION FlLED' APR. H. 1914.

Patented Nov. 16, 1915.

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3 SHEETS WITNESSES ,4 TTUR/VE rs s'rans VACUUM-PUMP.

To all whom it may concern Be it known that I, CHARLES N. SownEN, a subject of the King of Great Britain, and a resident of Soledad, Guantanamo, in the Republic of Cuba, have invented a new and Improved Vacuum-Pump, of which the following is a full, clear, and exact description.

My invention relates to vacuum pumps of the reciprocating type, and has reference more particularly to pumps used in connection with sugar refining.

The object thereof is to provide a simple, inexpensive and efficient pump whereby the said pump during its stroke can form a plurality of independent vacuums of predetermined. pressure. I attain the above object by providing a reciprocating vacuum pump wherein the sliding valve is adapted to bring into communication with the cylinder different vacuums at predetermined points of the voluminal displacement of the piston during the stroke in the cylinder.

The invention consists of the construction and combination of parts to be more fully described hereinafter and fully set forth in the claims. 4

' Reference is to be had to the accompanying drawings forming a part of this specification, in which like characters indicate corresponding parts in all the views, and in which:

Figure 1 is an axial section through the pump cylinder and chest; Fig. 1 is a diagrammatic view showing the pump cylinder connected to three receptacles having different predetermined vacuums; Figs. 2, 3 and 4 show the different positions of the sliding valve during the movement of the piston in the cylinder; Fig. 5 is a horizontal section on line '55, Fig. 1; Fig. 6 shows a modified structure of acylinder chest and slide valve therefor; Fig. 7 shows another modified structure ofa cylinder chest and slide valve therefor whereby two vacuums can be formed; Fig. 8 is a diagrammatic view showing the direction in which the valves check the fiowi Before proceeding to a more detailed description of my invention, it must be-understood that the highest vacuum of about twenty-seven inches is created first in the main suction, then the vacuum in the second suction depends upon the vacuum which has been created in the first or main suction, and the vacuum in'the third suction will depend Specification of Letters Patent.

Patented Nov. 16, 1915.

Application filed April 11, 1914. Serial No. 831,252.

upon the vacuum created in the second suction by the first, and so on. It will also be remembered that during the time the second and third suctions are being opened by the main valve, uncovering the ports in succession, the volume of the side of the piston connected to the second and third suctlons is decreasing. The slide or main valve should be so designed for the diflerent suctions that they will all have been successively opened before the piston will have reached the center of its stroke, as this is the greatest displacement of the valve in either direction. It must also be noted that while the pump herein described is mainly intended for use in sugar refining, the same can be applied to other industries as well.

Referring to the drawings, 7 represents a cylinder provided with ports 8 leading from the chest 9 to the ends of the cylinder. A port 10, between the ports 8, is connected by means of a pipe 11 to a receptacle 12 in which-the vacuum is to be about 27 inches. The chest 9 is also provided with vacuum inlet ports13 and 14, each exterior to the ports 8. The ports 13 lie intermediate the ports 8 and l iand are connected by means of a pipe 15 to a receptacle lfiwhich is under a vacuum of about fifteen inches. Ports 14 are connected by a pipe 17 to a receptacle 18 which is under a vacuum of substantially two inches. Thus, the ports 10, 13 and 14: of the chest are connected to independent receptacles.

, Positioned in the chest, 9 is a hollow slide valve 19, the hollow 20 of which is provided with ports 21 and 22 on the face controlling the ports 8, 10, 13 and 14. Valve-controlled openings 23 are provided in the slide valve 19 and form exhaust ports from the hollow 20 of the valve into the chest 9. The face of the valve controlling the ports 8, 10, 13 and 14 is provided with a central recess 24:, which recess is adapted to establish communication between the ports 8 and 10. The slide valve has also a bypassage 25 surrounding the reeess24, the purpose of which will appear hereinafter.

As the piston begins its stroke (see Fig. 2), the suction side has just been out off from the atmosphere by the slide valve 19, while the compression side has been cut off from the main suction, and the vacuum therein is at about twenty-seven inches. As the cut-01f takes place by the slide valve, the

will be noted that when passage 25 brings the two ends of the cylinder into communication, and the equilibrium between the two ends is established, bringing the vacuum of twenty-seven inches to about twenty-four inches. As the piston proceeds in its movement (see Fig. 3), the valve 19 brings the main suction in communication with the suction end of the cylinder, While the port 22 of the slide valve brings the compression end, which is at about twenty-four inches vacuum, into communication with the ports 13, and, therefore, the vacuum in the receptacle 16 is raised. It the discharge side of the cylinder is brought into communication by the slide valve 19 with the receptacle 16 there is a continuous reduction in volume on the discharge side; and the lowering of vacuum in the receptacle 16 is prevented by a check valve 29 positioned on the pipe 15 which connects the receptacle 16 to the chest.

As the piston proceeds in its movement (see Fig. 1), before the same reaches the middle of its course, the slide valve 19 brings the ports 14 leading to the receptacle 18 into communication with the discharge end of the cylinder by means of the ports 21 and 22, and thus establishes communication between the vacuum of about fifteen inches in the discharge end of the cylinder and the vacuum in the receptacle 18. The resulting equilibrium produces a predetermined vacuum in the receptacle 18. The continuation of the movement of the piston 26 will lower the vacuum in the discharge end of the cylinder; and the check valve 27 on the pipe 17 connecting the receptacle 18 to the chest prevents the lowering of the vacuum by the reduction in volume. A further movement of the piston" lowers the vacuum in the discharge end until the same reaches the atmospheric pressure. when it exhausts through the. hollow 20 of the slide valve 19 by raising the valve controlling the discharge opening 23. passing into the chest 9, and from there through the outlet 28 into the atmosphere. During the stroke of the-piston the suction end of the cylinder is in communi cation with the main suction, bringing this end of the cylinder to a vacuum of about twenty-seven inches.

It will be noted that the slide valie establi'shes communication between the consecutive lower vacuums after predetermined displacements of the piston; and the lowering of vacuums in the receptacles 12, 16 and 18 is prevented by check valves 27, 29 and 30 provided therefor, the check valve 30 may be dispensed with, as the conduit is controlled by the slide valve. In Fig. ithe piston is shown on its return stroke relatively to what was described in Figs. 1, 2 and 3. This position indicates the suction side connected to the main suction on the receptacle 12, and the discharge or compression side connected with the receptacle 18. It may be remarked that when the slide valve 19 brings a successive suction having a lower vacuum into communication with the hollow 20 of the valve, the preceding suction does not need to be cut ofi" by the valve, as the lowering of vacuum therein is prevented by the check valves provided on the pipes connecting the receptacles with the ports. From this it will be seen that the slide valve 19 opens the suction ports at predetermined displacements of the piston.

In the modified structure of the slide valve (shown in Fig. 6), the main suction is connected to the port 10. The secondary suction 31 is connected to the chest 9"and is equivalent to the port 13 of the previous de scription. The third suction 32 is positioned in the chest and is equivalent to the previously mentioned port 14. In this structure there are only five ports on the working surface of the chest, as compared to the seven previously stated. The slide valve 33 is not hollow but provided with apertures 34 in the laps of the valve, and also with a central passage 35. and thereby communication is established between the ports 8' and 10' and also between the ports 8 when the piston begins its stroke. The apertures 34 in the lap are adapted to establish communication between the ports 8 and the secondary and third suctions. As shown in thefigure, the vali e establishes communication between the main suction and the suction end of the cylinder, While the compression suction exhausts into theatmosphere through the valve 36 of the chest 9. I

In Fig. 7 a modified structure of the slide valve isshown. In this case the cylinder is intended only for two predetermined vacuums, a main vacuum and a secondary vacuum., The main suction 10"- is between the ports 8". The secondary suction 13 is outside of the ports 8 and is shown to be controlled by check valves 37 which lead to the proper receptacle. The figure shows the pis-. ton at the end of the stroke, the arrows indicating the direction of the reciprocating parts at this point. It will, be seen that the main suction has just been closed by the edge of the central recess in the valve, and the discharge by the outer edge of the valve. In the return movement of the piston, the ports 8" will be brought into communication by the by-pass 25", and then communication will be established between the secondary suction and the discharge side of the piston substantially as described.

It is evident that various changes might be made and modifications resorted to in the construction and arrangement of the parts described without departing from the spirit and scope of my invention; hence, I do not wish to limit myself to the exact construction shown.

Having thus described my invention, I claim as new and desire to obtain by Letters Patent:

1. The combination of receptacles with a reciprocating vacuum pump, said pump comprising a cylinder having a chest, said chest having ports connected to the ends of the cylinder and to said receptacles; a piston in the cylinder; means for actuating the piston; a hollow slide valve in the chest adaptedt'o establish communication between some of said receptacles and the cylinder through the hollow of the valve, said valve having means for establishing communication between the other receptacles and the cylinder independent of the hollow; and means synchronizing the movement of the valve with the piston whereby said piston is adapted to create an independent vacuum in each of said receptacles at both sides of said piston during each stroke of the pump, the highest vacuum being formed through the means in the valve independent of the hollow.

2. The combination of receptacles in which different vacuum pressures may be established with a reciprocating vacuum pump, said pump comprising a cylinder having a chest; a piston in said cylinder; means for actuating the piston, said chest having a plurality of ports; conduits connecting said receptacles with some of said ports, said cylinder having conduits from the other ports to the ends of the cylinder; a slide valve in said chest controlling said ports; and means synchronizing the movement of said valve and piston so that said valve is adapted to bring the receptacle in which the high est vacuum is to be established into communication withthe cylinder on the suction side of the piston on each stroke thereof and to bring the receptacles in which consecutively lower vacua are to be established into communication with the cylinder on the same side of the piston upon its return stroke.

3. A vacuum pump comprising a cylinder having a chest; a piston in said cylinder; means for actuating the piston, said chest having a plurality of ports, said cylinder having conduits connecting some of the ports to the ends of the cylinder; a hollow slide valve in the chest controlling the ports therein, said hollow of the valve adapted to establish communication between the ports:

connecting the cylinder and the other ports in the chest; and means synchronizing the movement of the valve and piston, said hollow valve having a by-pass adapted to establish communication between the ports connected to the ends of the cylinder substantially as and for the purpose set forth.

4. In combination, receptacles under different vacuum pressures; a reciprocating vacuum pump and conduits connecting the pump to each receptacle, said pump comprising a cylinder, a piston therein, a slide-valve controlling the communication of said cylinder with the conduits, and means synchronizing the movement of the piston and the valve whereby said valve is adapted to establish communication between each of said receptacles and said cylinder independently during each stroke.

5. In combination, receptacles under different vacuum pressures, a reciprocating vacuum pump, conduits connecting the pump toeach receptacle, said pump comprising a cylinder, a piston therein, a slide valve controlling the communication at said cylinder with the conduits, and means for synchronizing the movement of the piston and the valve, said valve having means whereby vacuums of predetermined pressure differences at both sides of the piston in the cylinders can be formed during each stroke of the pump, said valve being adapted to establish communication between each of said receptacles and said cylinder during each stroke at a predetermined pressure in the cylinder, the highest vacuum of the pump being formed on the suction side and the lower vacuums on the compression side.

In testimony whereof I have signed my name to this specification in the presenceof two subscribing witnesses.

, CHARLES N. SOWDEN.

Witnesses C. F. FERRER, M. B. PUENDL. 

